1. Technical Field
The present invention relates to a clutch release mechanism used to release the engagement of a multiple disk clutch device installed in a power unit, which may be freestanding, or alternatively, which may be incorporated into a vehicle such as a motorcycle, an all-terrain vehicle or the like.
2. Background Art
There is known a clutch release mechanism of a multiple disk clutch device configured as below, as disclosed in e.g. Patent Document 1 mentioned below. A plurality of balls are interposed between a fixed cam plate and a movable cam plate which are opposed to each other. A release member is pressed by use of a thrust force generated by the relative turning of both the cam plates to release the engagement of the clutch.
When the clutch release mechanism configured as disclosed in Patent Document 1 is assembled, the following is necessary. The movable cam plate is engaged with a pressure-applying plate and the balls are arranged on the movable cam plate. A fixed cam plate mounted to a case member covering a multiple disk clutch device is mounted along with the movable cam plate so as to hold the balls therebetween at accurate positions.
However, when the case member is assembled, it is necessary to perform the assembly while maintaining the state where the balls are received in the recessed portions of the movable cam plate. Therefore, there is a problem of poor workability.
In addition, to solve such a problem, for example, Patent Document 2 mentioned below discloses a clutch release mechanism as below. A retainer for balls is attached to a fixed cam plate. A plurality of balls are attached as a ball unit. The ball unit is prevented from coming off by a retaining member. A movable cam plate is fitted to a release member.
However, in the case of the clutch release mechanism configured as in Patent Document 2, a cylindrical boss portion of the fixed cam plate is inserted into the fixed cam plate. In addition, the relative positions of the respective axes of the movable cam plate and the release member are fixed. Therefore, to prevent the misalignment between the fixed cam plate and the movable cam plate, it is necessary to significantly reduce the cumulative tolerances from the clutch member to clutch inner member of a multiple disk clutch device.    Patent Document 1—Japanese Patent Laid-Open No. 2005-249083 (FIGS. 1 and 2)    Patent Document 2—Japanese Patent Laid-Open No. 2007-177873 (FIGS. 1 to 8)